Organelles

Question 1

Centrosome

Answer 1

centrally located microtubule organizing center. Contains a pair of centrioles that separate to form spindle poles during mitosis.

Question 2

Cytoskeleton

Answer 2

organizes the cell structure, shape and arrangement of subcellular organelles. Consists of 3 major components: microtubules, thin filaments (actin), and intermediate filaments.

Question 3

Cytoplasm

Answer 3

everything inside the plasma membrane excluding the nucleus

Question 4

Cytosol

Answer 4

fluid surrounding the organelles

Question 5

Endoplasmic reticulum

Answer 5

Network of membranous tubules that extend from the nuclear envelope throughout the cell. Major site of protein and membrane lipid synthesis. Regions with ribosomes attached to the cytosolic surface are called rough ER and regions without are smooth ER

Question 6

Endosomes

Answer 6

series of organelles that sort endocytosed materials sending them to lysosomes or back to the plasma membrane

Question 7

Golgi apparatus

Answer 7

consists of a stack of flattened sacs that can be divided into 3 compartments; cis golgi network, medical golgi stacks, and trans golgi network. Proteins and lipids synthesized in the ER are delivered to the golgi stack where they’re modified, sorted , and packaged for secretion or delivery to lysosomes or the plasma membrane

Question 8

Lysosomes

Answer 8

low pH organelle containing digestive enzymes that work best at low pH. responsible for digesting worn out or unwanted organelles as well as macromolecules and particles taken into the cell by endocytosis. The digestion products are typically re-used by the cell.

Question 9

Mitochondria

Answer 9

powerhouse of the cel generating most of the ATP required by mammalian cells via fuel oxidation and oxidative phosphorylation. Contains two membranes separating the mitochondrial matrix from the cytosol. Inner membrane is extensively folded to form cristae containing the electron-transport chain and ATP synthase. Contains its own small circular DNA in the matrix compartment that encodes a handful of proteins.

Question 10

Nucleus

Answer 10

typically the largest and most prominent organelle in the cell. Surrounded by a double membrane (nuclear envelope) containing nuclear pores that control passage of macromolecules into and out of the organelle. Contains DNA in the form of chromosomes, and is the site of DNA replication and transcription.

Question 11

Nucleolus

Answer 11

substructure within the nucleus responsible for the transcription of processing of rRNAs and for assembly of ribosomal subunits.

Question 12

Peroxisomes

Answer 12

small organelles containing enzymes involved in the oxidative reactions that break down lipids and destroy toxic molecules. Reactions produce toxic hydrogen peroxide which can be used in oxidative reactions or degraded.

Question 13

Plasma membrance

Answer 13

Separates the cell interior from the exterior and acts as a permeability barrier. Composed of a lipid bilayer containing embedded proteins. Many of the lipids and proteins in the membrane contain covalently attached carbohydrate chains on the outer surface.

Question 14

Proteasomes

Answer 14

cylindrical protein degradation machines located in the cytoplasm responsible for most of the protein turnover in the eukaryotic cell. Proteins destined for degradation are tagged with ubiquitin and fed into the cylinder where proteases chop them up into short peptides that are then released into the cytosol.

Question 15

Riobosomes

Answer 15

particles composed of RNA and protein, responsible for catalyzing the synthesis of proteins